28957561 has 2 divisors, whose sum is σ = 28957562. Its totient is φ = 28957560.

The previous prime is 28957559. The next prime is 28957637. The reversal of 28957561 is 16575982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25441936 + 3515625 = 5044^2 + 1875^2 .

It is a cyclic number.

It is not a de Polignac number, because 28957561 - 2¹ = 28957559 is a prime.

Together with 28957559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28957531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14478780 + 14478781.

It is an arithmetic number, because the mean of its divisors is an integer number (14478781).

Almost surely, 2^28957561 is an apocalyptic number.

It is an amenable number.

28957561 is a deficient number, since it is larger than the sum of its proper divisors (1).

28957561 is an equidigital number, since it uses as much as digits as its factorization.

28957561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 151200, while the sum is 43.

The square root of 28957561 is about 5381.2230022552. The cubic root of 28957561 is about 307.0817403750.

The spelling of 28957561 in words is "twenty-eight million, nine hundred fifty-seven thousand, five hundred sixty-one".